The invention relates to hand-held jack-knives, provided with slop catches or not.
Numerous embodiments of such knives are known, but the use thereof in certain fields of activity requires them to be attached to their user by means of a suitable attachment means; this is the case in particular for the field of mountain climbing, pot-holing, deep-sea fishing, water and aerial sports, etc. In other circumstances, they have to be fixed or attached to a fixed support, for example for presentation, and maybe for theft prevention purposes, on a stand.
It is of course sufficient to drill a hole in the handle of said knives to meet this requirement, but this hole that has to be sufficiently large for the attachment to pass through (for example a mountaineering snap-hook) has to be placed on an extension of the handle so as not to hamper full closing of the blade and has to be of a diameter appreciably smaller than the largest transverse dimension of said handle. The invention proposes to overcome this difficulty without increasing the longitudinal dimension of the knife.
In the following description, we will designate by:
longitudinal plane of the knife: a plane parallel to the mid-plane of the blade.
longitudinal direction of the knife: a direction parallel to the longitudinal plane extending appreciably from the free end of the handle to the free end of the blade, the knife being in the open position.
A knife according to the invention is therefore essentially formed by a handle and a blade articulated around an axis of rotation. This articulation is formed by a hollow bush, the axial opening thereof perpendicular to the longitudinal plane of the knife and the dimension thereof adapted to the size of the attachment or of the fixing means used, passes completely through the handle and is secured in rotation to the knife blade. This opening may be of cylindrical shape but will preferably have a tapered shape towards the outside, for example in the form of a half-ring. This shape makes it easier to insert the attachment or adapts better to fit the curvature of the fixing means (padlock bow, mountaineering snap-hooks).
This bush is generally fixedly secured in rotation to at least one operating means, external to the handle, enabling the blade to be opened and closed.
This operating means is formed for example by one or two circular knobs. The knob is externally ribbed and/or presents raised external parts so as to be able to be operated easily with the thumb or another finger of one hand.
The stop catch is formed by at least one flexible tab. One end thereof is fixedly secured to the handle of the knife and the other, free end thereof, engages by spring effect in a suitable housing of the bush-knob assembly when the blade is fully open. This full opening is determined by the heel of the blade pressing on a stop placed in the handle of the knife.
The tab is either flexible or rigid and articulated at its base around an axis of rotation appreciably parallel to the longitudinal plane of the knife and subjected to the action of a flexible means (spring, elastomer, etc.) acting towards the outside.
The tab presents a flat and elongate shape in the active part thereof; the length of the tab is arranged either in an appreciably radial direction or in an appreciably tangential direction with respect to the rotation movement of the blade on the handle.
The housing situated in the bush-knob assembly presents, in a cross-section parallel to the axis of rotation and in a tangential direction with respect to the rotation movement, the shape of a straight prism of trapezoid cross-section the large base thereof is directed towards the end of the tab. The bearing plane on the end of the tab presents an incline of 8xc2x0 and 12xc2x0 with respect to the axis of rotation.
This arrangement enables the blade to be locked in the open position of the knife and enables any mechanical play due to machining and initial assembly tolerances and/or wear of the moving parts in use to be compensated. The bearing planes of the end of the tabs preferably present the same incline.
The spring effect of the tabs is exerted outwards, the end housing being preferably situated on the internal face of the knob parallel to the longitudinal plane of the knife.
To release the stop catch and close the blade, one or two push-buttons can be provided in the handle to push the tab outwards and thus allow the bladexe2x80x94bushxe2x80x94knob assembly to rotate with respect to the handle.
It should be noted that the tab can also be used, the knife blade being in the closed position, to create a hard friction preventing the blade from opening accidentally. In this case, a housing in the form of a trapezoid prism, similar to that of the stop catch, is also made in the bush-knob assembly but the incline thereof is 45xc2x0 to 80xc2x0 in order to enable the tab to be pushed inwards by a small opening force of the blade exerted on the knob or the blade.